Lathe attachment



Get. 13 1925. 1,556,949

H. c. MALL LATHE ATTACHMENT Filed Ana. 4. 1924 .5 Sheets-Shest 1 li i wveutoz liking; Gill all attouww Oct. 13, 1 1,556,949

- H. c. MALL LATHE ATTACHMENT Filed Aug. 4. 1924 3 Sheets-Sheet 5 iii?- 'IA] 'IIIIIIIIIIIIIIIIIIIIIIJ Patented Oct. 13,

UNITED "STATES PATENT OFFICE.

my c. m, ormnunuoms, moms. I

1.1mm a'r'rlacnunnr.

Application filed new 4, 1924. Serial in. 729,997.

ments, of which the following is'a specification.

This invention is an attachment for lathes and is designed for use in machining convex and spherical surfaces wherein the form or contour of the'work is generated radially. A particular object of the invention is to provide an attachment in which the curve is generated by the machine alone, thereby relieving the operator of-the necessity of guiding or directing the device and, therefore, eliminating the possibility of an error in a the contour occurring through inattentiveness or incompetence on the part of the op erator. i

A further object is to provide an attachment of the nature referred to which is combined with, and embodied in a compounddevice will be a parent from the following description an from the accompanying drawings, wherein:

Fig. 1 is a fra entary view, in side elevation, of a lat e of conventional design with the attachment in lace thereon. Fig. 2 is a top plan view of t e same. Fi 3 is a cross section of the lathe illustrating the manner in which the device is associated with the carriage of the lathe. Fig. 4 is a vertical cross section of the attachment and lathe carriages, illustratin the manner in which the parts of the attac ment are assembled and mounted upon the carriage. Fi 5 is a vertical longitudinal section along ine 5-5 of Fig. 2., Fig. 6 is a sectional view along line 6-6 of F1 5, and Figures 7 ahd 8 are detailed views 0 the socket drive shafts forming part of the invention.

In the drawings, 10 designates the work which is held in chuck jaws 11 of the lathe, and 12, the lathe carriage upon which the attachment is mounted. The compound slide 13 of the attachment is dovetailed for I sliding adjustment with a base member '14 as shown at 15 and the tool is held in the ordinary manner in a tool post 16 which en-- ters the tool slot 17 of theslide. The feed of the tool with respect to the work 10 is regulated and'contro led inthe usual manner b the feed screw 18 arranged within a lon u tudinal oove 19 on the underside of t e sl1de13 y which it is carried. This screw is thread'edly engaged with a nut 21 stationary with the base 14, as shown in Figs, 4 and 5, and is o eratedby the hand wheel 20.

A cross-s ide 22 of substantially the. usual. type is dovetailed with the ways 23 of the lathe carriage 12 for movement crosswise of v the lathe, being equipped with the usual nut 24 engaged with the cross-slide feed screw 25 of the carriage. As is customa, feed screw 25 may be operated by handweel 26 for automatic operation. For purposes of the present invention, the cross-slide is provided adjacent one end with a raised circular ortion 28 adapted to serve as the main base Fig. 6, and has an integral shaft which is journaled between removable bearings closmg opposite ends of the pocket; one end of the worm shaft being exposed exteriorly of the pocket and squared-for enga ement in the socket of. one ofthe socket drive shafts hereinafter referred to. The square hub of or thrown in mesh with the lead screw 27 the worm gear engages in a s uared recess 34 in the underside of thelsli e base 14 so that the said base and the slide 13 will be turned with the gear, and the base 14 is formed with a flange 35'ada ted to bear on the flange 36 of the cross-sli e; both flanges being tapered and locked to ether by a twoart clamping ring 37 as i1 ustrated, therey providing a swivel joint between the compound rest and the cross-slide. To provide for adjusting the tool for various diameters, the slide 13 has a tool slot 47 cut lon itudinally thereof and at a right an Is to t e slot 17 This slot 47 is of particu ar advantage in enabling the tool post'to be set generate a lar back considerably when it is required to radius. A plate 38 1s secured to the far side of the cross-slide carriage 12 and supports the extended end of the worm shaft upon which is keyed the small gear 40 on the end of a shaft 41 which is coupled b a sleeve 42 to a socket drive'shaft 43. is indicated at 43 and 43 in Figures 7 and 8 several socket shafts of different lengths may be provided each havin a socket at one end to receive the squar end of the worm shaft and being grooved at 44 to provide a lock slot to be engaged by the key 45 of the coupling sleeve.

In using the device, nut 24 of the crossslide is first removed from the cross-slide feed screw 25 so that the cross-slide 22 will remain stationary during operation of the lathe. The movement of the cross-slide screw 25 will, therefore, be transmitted only to the gear 30 which will be revolved so as to swin the compound slide in the arc of a circle, t iereby generating the desired radius and developing the spherical surface 46 of the work.

The worm 32 is provided with a graduated dial 48 and gear 30 is preferably a 90-tooth gear with worm pitch to suit, so that each revolution of the worm equals 4 degrees or one tooth of the gear; the dial on the worm being divided into four equal parts or 4 degrees. Each quarter division of the dial, equallin 1 degree, is subdivided into minute gra nations. Hence, in cutting a radius 5 degrees, 17 minutes, the worm would make 1 turns and 17 minutes which equals 5 degrees 17 minutes.

From the foregoing it will be apparent that the attachment can be readily and conveniently applied to lathes' of standard types and will greatly "facilitate the rapid and accurate production of work. Moreover, it is to be understood that the invention is not limited to the precise details of construction and arrangement asare herein set forth but is susceptibleof such variation and modifications as fall within the scope of the appended claims.

ting cket tangent to the recess, a worm ear oosely seated in the said recess and aving a square upwardly extending hub, a worm screw within the said pocket and engaging the said worm gear, means for rotating the said worm screw, a rotatable slide base seated u on the said raised portion of the cross-sli e, said slide base having a flange adapted to bear on the said flange of the said raised portion and also having a squared recess in its underside to accommodate the square hub of the said worm gear, a longitudinally adjustable slide carried by the said slide base, and a removable clampm ring embracin the said flanges and hol ing the cross-slide and slide base against separation while permitting relative rotation thereof.

2. A lathe attachment comprising a crossslide presenting a raised central portion having a horizontal bearing face provided with a. central recess and a communicating pocket tangent to the recess, a worm gear removably seated on the bottom of the said recess and presenting a square upwardly projecting hub, a compound slide including a base member resting upon the said bearin face of the said raised portion of the sai cross-slide and presenting a square recess in which the said squared hub of the worm gear engages, removable bearings closing 0 posite ends of the said pocket, a worm s aft journaled in said bearlngs and havin an end extended exteriorly of the sai pocket, a worm within the said ket, said worm being carried by the sai shaft and being in driving engagement with the said worm gear, and a drive shaft detachably engaged with the exposed end of the said worm shaft. y

In testimony whereof I aflix my signature.

HENRY C. MALL. 

